Designed as a creative tool, the Radial X-Amp is an active re-amplifying device that allows prerecorded instrument tracks to be sent through guitar amplifiers and effect devices.

With the X-Amp, you could for instance take a pre-recorded guitar track, and send it through a second distortion pedal and amplifier and then slightly delay the track to add a thick doubling effect. You could also use the X-Amp from a voice track to a distortion pedal to ad some grit to a performance. Another popular use would be to go back and fix a track should an error or glitch somehow appear.

Although the Radial X-amp is new, the process of re-amping tracks has been around for years. Historians credit jazz guitar great Les Paul as the first to employ the concepts of re-amplifying sound in the 1950s as there was no other way to double tracks or create echo effects. In the 1960s, Phil Spector’s work with his famous ‘wall of sound’ employed re-amping techniques. In the 1970s, Roger Nichols built his own ‘re-amper’. Roger used it on all of the Steely Dan records virtually burning out tubes in effort to get the right sound. Only today with the proliferation of affordable high quality multi-track recording has the demand for high-quality recording tools allowed manufacturers to develop devices such the Radial X-amp into commercially viable products.

This is not to say that other re-amping devices have not been available. In 1980, Jensen® Transformers introduced the 1st transformer that could effectuate the process and included an application note on the spec sheet discussing the conversion of balanced to unbalanced guitar signals. The Radial JDI Mk3 in fact employs a newer version of this same transformer and can be easily used as a re-amping device. (See the Radial JDI Owner’s manual for more details).

The forefather to the Radial JD7 Injector (custom built by Radial Chief Engineer Denis Rozon circa 1990) was designed to drive a signal to several guitar amplifiers at once and the introduction of the 1st generation Radial JD7 in 2001 added facilities such as balanced output and input to simplify the re-amping process. The Radial X-Amp is in fact a derivative of the Radial JD7 Injector. It employs the same active balanced input and new Class-A circuit topology as the popular JD7, but in a more affordable and simplified two output configuration.

More detailed information can be found in the The History of re-amping article.

The Challenges in building a better re-amping device

Up until the X-Amp, pretty much all re-amping devices have been passive, transformer-based. These generally work well but do have limitations: Because the same transformer is used to both convert the balanced line level to an unbalanced signal while changing the impedance, one is required to employ workable compromise to get an acceptable tone. Because varying the output level is required to properly match the amplifier’s input level, a potentiometer is required. Since a potentiometer is in fact a variable resistor, changing the level will introduce a load variation, which will inevitably impact the tone. This is not to say that the tone will be bad, it just means that finding the ‘sweet spot’ may be compromised.

The Radial X-Amp was designed in such a way as to solve these problems. To begin, the X-Amp is active. This means that it is equipped with an external power supply to provide the DC to the circuit. The circuit itself is Class-A meaning that it employs a high performance, audiophile buffering circuit to ensure the cleanest and most natural tone. This design allows us to ad several important features and controls that are not possible with simple passive devices. For instance, we introduced a peak-overload detector that lets you monitor the level coming from the recorder and ensure the signal will not overload the circuit. Because we are active, the X-Amp’s output control can be adjusted at will without affecting the tonal character. Furthermore, by adding a second buffer to the signal, we can introduce a second output that to drive a stereo amp set-up or maybe two completely different amps and effects chains at one time. This opens the doors to significantly greater tonal possibilities!